This invention relates in general to the extraction of metals from sea water and in particular to a system and method for the continuous extraction of uranium utilizing flexible adsorber sheets which are first deployed in currents of sea water for adsorption of a metal and then recovered for elution of that metal.
The recovery of metals generally from sea water is by no means a novel subject but the costs associated with most techniques have rendered them impractical. It was early recognized that enormous quantities of sea water would be needed for any practical production and that the siting of the extraction facility would have to be carefully chosen to ensure an adequate inflow of fresh sea water and the avoidance of recirculation of depleted sea water through the facility.
Various approaches have been considered. Studies of oceanographic data have indicated that in certain areas of the world a fairly constant current is available to meet certain of the criteria for a practical facility. Tidal schemes have also been proposed where a large area of water may be enclosed in a lagoon for extraction of metals followed by a tidal discharge of the depleted water and tidal refilling of the lagoon. Also, several pumped-water schemes have been proposed. However, a broad range of problems including large capital and operating costs, environmental aspects, energy requirements, availability and characteristics of proposed sites and even political factors have prevented the realization of any of the proposals. It is a major object of this invention to avoid or overcome the problems associated with previous proposals and to provide a practical system and facility for the continuous extraction of metals from sea water.